The present invention relates to the production of baked wheat-based snacks having a chip-like crispy texture and surface bubbles.
Cohesive, machinable doughs which can be sheeted, stretched, and cut into pieces may be produced at room temperature when the doughs possess a high content of wheat or other gluten-containing flour. The baking of conventional wheat-based doughs into crackers provides a lamellar structure with generally uniform small cells and a tender, mealy, leavened texture. Upon mastication, the conventional crackers generally disperse more rapidly than does a chip. They do not provide a crunchy texture and a sensation of breaking into pieces with low molar compaction before dispersion as does a chip. Additionally, crackers are generally dockered to prevent pillowing and to provide a generally flat bottom surface and a blistered top surface. Oyster or soup crackers and snack crackers which have a pillowed appearance may be produced from wheat-based doughs by the elimination of dockering holes. However, these products still possess a leavened, tender, mealy texture and a cracker appearance, rather than a crisp, crunchy chip-like texture and chip-like appearance.
Filled baked crackers or snacks obtained by needle injection of fillings into hollow expanded snacks made from wheat flour are disclosed in U.S. Pat. No. 4,209,536 to Dogliotti, U.S. Pat. No. 4,613,508 to Shishido, U.S. Pat. No. 4,752,493 to Moriki, and U.S. Pat. No. 5,000,968 to Szwerc et al. Production of a chip-like snack having surface bubbles and surrounding crisp, thin regions is not disclosed in these patents. The doughs are formulated and processed to retain a puffed or pillowed shape after piercing of the baked/hollow piece.
A cellular structure is obtained by the use of egg white in the shell of the pastry product of U.S. Pat. No. 4,209,536 to Dogliotti.
In the process of U.S. Pat. No. 4,613,508 to Shishido, hard dough biscuits are prepared by baking a dough having 10-30 parts by weight of sugar, 10-25 parts by weight of edible fat or oil, 1.5-4.0% leavening agent, and 20-35 parts by weight of water per 100 parts by weight of cereal flour to obtain a degree of leavening of at least 280%.
The baked hollow expanded snacks in the form of a figure such as an animal or vehicle of U.S. Pat. No. 4,752,493 to Moriki are produced from a farinaceous raw mixture. The raw mixture is prepared by mixing from 60-95 parts by weight of at least one low swelling-capacity farinaceous material and 40-5 parts by weight of at least one high swelling-capacity farinaceous material. The low swelling-capacity material may be a non-glutinous cereal such as wheat, rye, maize, non-glutinous rice, sago, sorghum, triticale, millet and beans, or starches separated from these sources. The high swelling-capacity material may be potato, taro, tapioca, arrowroot, sweet potato, glutinous rice, waxy corn, or starches derived from these sources having their cell walls broken. The farinaceous raw mixture is partly gelatinized prior to rolling into a smooth sheet by the addition of hot water or by the action of steam, so as to raise the temperature of the farinaceous raw mixture to 65xc2x0 C. to 90xc2x0 C. According to Moriki, upon baking, the starch in the surface of the dough pieces is gelatinized, thereby forming a skin having good gas-holding capacity and excellent stretchability. Water and volatile materials in the dough pieces push the skin outward upon heating, so that the dough pieces expand and are internally split into two layers or shells, forming a hollow space therebetween.
The filled crackers of U.S. Pat. No. 5,000,968 to Szwerc et al. are produced from a dough containing proteolytic enzymes. The enzymes hydrolyze proteins of the flour, which relaxes the dough and thereby permits a hollow center to be formed, rather than a cellular center, as the cracker expands under the influence of the leavening agent during baking. This, it is disclosed, strengthens the shell of the cracker and permits the cracker to be filled by means of an injection needle piercing the surface of the cracker.
The production of chip-like, starch-based snacks having a crispy texture and surface blisters from starch-based compositions which have little or no gluten, such as potato flour or corn flour, is disclosed in U.S. Pat. Nos. 4,873,093 and 4,834,996 to Fazzolare et al. and U.S. Pat. Nos. 5,429,834 and 5,500,240 to Addesso et al. Starch-based compositions which have little or no gluten, when mixed with water, do not form a dough that is cohesive at room Temperature and continuously machinable or sheetable. Machinability of doughs made from ingredients having little or no gluten may be improved by forming a dough under elevated temperature conditions, such as by steaming the ingredients, as disclosed in U.S. Pat. Nos. 4,873,093 and 4,834,996 to Fazzolare et al.
In the process of U.S. Pat. Nos. 5,429,834 and 5,500,240 to Addesso et al, use of a pregelatinized waxy starch provides for the production of cohesive, extensible, continuously machinable doughs from starchy materials or ingredients having starch with no or low gluten. These machinable doughs may be formed at room temperatures without the need for steaming or heat treatment to develop cohesiveness, extensibility, and machinability.
U.S. Pat. Nos. 4,931,303 and 4,994,295 to Holm et al disclose that in the production of fabricated snack products having controlled surface bubbling, the dough sheet must have cohesive properties which permit the surface or surfaces of the dough or preform to stretch relatively uniformly when forming bubbles during frying. The highly cohesive, non-adhesive dough, it is disclosed, can be made by adjusting the quantity of free gelatinized starch, the degree of retrogradation of the starch (thereby affecting the water absorption of a given quantity of the starch), and the concentration of any starch-complexing emulsifiers present. In the Holm et al process, a dough may be formed comprising, e.g., potato solids or corn solids, raw or pregelatinized starches, modified starches, flavorings, oils, and the like. For producing potato snacks, the preferred major ingredient in the potato dough is a dehydrated potato flake with high water-absorption capability. The dry ingredients are placed in a mixer and blended with water to obtain a dough having a moisture content of from about 30% to about 55%. According to Holm et al., higher moisture content means higher oil absorption during frying. It is further disclosed that doughs containing less than about 30% moisture are generally too dry, after the Holm et al. drying step, to create adequate bubbles. In the Holm et al. process, substantial moisture reduction of the dough is achieved by frying. During frying, the dough moisture content of about 30% to about 55% is reduced to obtain a fried product with a moisture content of about 1-2%.
U.S. Pat. No. 4,560,569 to Ivers discloses that in the production of a dough-based fried food product, a processed starch in either gelatinized or ungelatinized form is frequently added when a low-starch flour or flake is employed. Water, it is disclosed, is required to soften the flour, and depending upon the protein content of the flour, to form a network of protein (gluten), which is the framework of the product. According to Ivers, starch, which is present in flours, is used as a binder and is required for the unleavened product to expand upon frying. Dough stickiness and hardness of the cooked product may be controlled by the addition of oil to the dough to control the extent of the protein framework. The dough is prepared by adjusting the ratios of components and the mixing time to allow it to sheet uniformly at the desired thickness without sticking or tearing. According to Ivers, addition of a small amount of a lecithin-in-water suspension to the formulation of the dough-based fried snack foods improves the transfer, sheeting and cutting, and significantly reduces clumping during frying, without the rapid buildup of free fatty acids and without significant darkening of frying oil, normally associated with the frying of foods containing lecithin.
In the production of wheat-based baked snacks, it has been found that the inclusion of a pregelatinized starch in the dough to create surface bubbles tends to result in a styrofoam-like or compressible texture, rather than a highly crisp, crunchy texture. Also, if the pregelatinized starch is not sufficiently hydrated prior to baking, bubbles created during baking tend to collapse.
In the present invention, wheat-based, chip-like snacks having a crisp, crunchy chip-like texture and bubbles distributed over their surfaces are produced from cohesive, machinable, sheetable doughs, without using a frying step for substantial moisture reduction of the dough, thereby resulting in products having low fat content. Surface bubbles comprising air pockets which extend from opposing surfaces are created and maintained during baking. The bubbles are maintained in portions of the baked dough, even though surrounding or adjacent portions of the dough have been dockered or punctured before baking. A pregelatinized waxy starch provides an extensible surface film prior to baking, which helps to temporarily trap moisture below the expandable film surface upon baking. A pregelatinized potato starch, which is also activated (i.e. sufficiently hydrated) prior to baking, helps to reduce or control bubbling and to avoid a styrofoam-like texture. It produces a crispy, crunchy, substantially unleavened texture in portions of the snack adjacent to the bubbled portions, as well as in the bubbled portions. In addition, the machinable, continuously sheetable, wheat-based dough may be produced at low temperatures. Sufficient hydration of the pregelatinized waxy starch and pregelatinized potato starch may be achieved by premixing them with hot water or by providing sufficient dough lay time for hydration to occur. The crispy, bubbled, wheat-based snacks of the present invention include non-fermented and fermented reduced fat, low-fat, and no-fat baked products, as well as full-fatted non-fermented and fermented baked products.
The present invention provides a baked, wheat-based, chip-like snack having surface bubbles comprising air pockets extending both above and below the substantially unleavened, adjacent portions of the snack. Dockering or piercing of the dough prior to baking results in localized unleavened or thinned areas and does not prevent the attainment of a plurality of discrete bubbles. Non-fermented and fermented reduced fat, low-fat, and no-fat baked products, as well as full-fatted non-ferrnented and fermented baked products, may be produced on a mass-production, continuous basis in accordance with the present invention. They are produced by admixing wheat flour, a film-forming, bubble-producing, pregelatinized waxy starch, and a pregelatinized potato starch with water to hydrate the starches and produce a machinable dough. Pregelatinized waxy maize starch is the preferred pregelatinized waxy starch. The pregelatinized potato starch produces a crisp, crunchy texture in the baked snack which would otherwise possess a styrofoam-like or compressible, leavened texture.
Uniform hydration of the pregelatinized waxy starch prior to baking is critical for producing bubbles during baking and for retaining the bubbles during baking and after baking. Also, uniform hydration of the pregelatinized potato starch prior to baking is critical for controlling bubbling caused by the pregelatinized waxy starch and for controlling texture of the bubbled and unbubbled portions of the snack chips. In embodiments of the invention, preheated hot water or fermentation lay time are used to at least substantially uniformly hydrate the pregelatinized waxy starch and the pregelatinized potato starch. Use of the gluten-containing wheat flour and bubble-forming amounts of the pregelatinized waxy starch provides for the production of a cohesive, non-sticky, extensible, continuously machinable dough. In embodiments of the invention, a modified potato starch which is activated during baking may be used to enhance surface bubbling and crispiness of the bubbled portions and unbubbled portions.
The machinable doughs of the present invention may be formed at room temperatures, without the need for steaming or heat treatment to develop cohesiveness, extensibility, and machinability. The doughs may be machined using conventional cracker-dough technology, involving sheeting, dough-sheet lamination, dough-sheet thickness reduction, and cutting of the dough sheet into pieces.
In embodiments of the present invention, the dough pieces have a moisture content of from about 20% to about 50% by weight, preferably from about 23% by weight to about 38% by weight, more preferably from about 25% by weight to about 35% by weight. The moisture content of the dough pieces is reduced from these high levels to less than about 10% by weight, preferably less than about 5% by weight, most preferably less than about 3.5% by weight, by baking the pieces. This moisture reduction by baking results in baked pieces each having a plurality of surface bubbles distributed throughout their surfaces. The pieces may also include blisters interspersed with the bubbles. In embodiments of the present invention, frying may be performed subsequent to baking. The avoidance of flying for substantial moisture reduction of the dough pieces permits the attainment of crisp, chip-like snacks having a vegetable shortening or oil or fat content less than 20% by weight of the finished product.
In preferred embodiments of the present invention, a baked, wheat-based, chip-like snack having surface bubbles and the texture and appearance of a potato chip, but the taste or flavor of a fermented or non-fermented cracker, may be produced without a leavened, mealy texture.
The baked wheat-based snacks may be produced by admixing: 1) wheat flour, 2) the pregelatinized waxy starch in an amount of from about 3% by weight to about 20% by weight, preferably from about 5% by weight to about 15% by weight, based upon the weight of the wheat flour, 3) the pregelatinized potato starch in an amount of from about 1.5% by weight to about 20% by weight, preferably from about 3% by weight to about 13% by weight, based upon the weight of the wheat flour, 4) from 0% by weight to about 20% by weight, preferably from about 5% by weight to about 18% by weight, of the optional modified potato starch, based upon the weight of the wheat flour, and 5) water to hydrate said starches and to form a machinable dough having a moisture content of preferably from about 23% by weight to about 38% by weight. The total amount of said potato starches is preferably less than about 30% by weight, most preferably from about 8% by weight to about 25% by weight, based upon the weight of said wheat flour. In embodiments of the invention, the weight ratio of the amount of the pregelatinized waxy starch to the total amount of the potato starches is from about 0.45:1 to about 1:1
The dough may then be laminated upon itself, reduced in thickness to form a thin sheet, and then cut into pieces. The dough pieces are heated to reduce their moisture content and to obtain chip-like products having a bubbled appearance and a crisp texture and which make an audible crunching sound upon mastication.